Electrical connector and spring contact therefor



Sept. 3, 1940. R. A. WALKER 2,213,293

ELECTRICAL CONNECTOR AND SPRING CONTACT THEREFOR Filed Dec. 1. 1937 Patented Sept. 3, 1940 UNITED STATES PATENT OFFICE ELECTRICALl CONNECTOR -AND SPRING CONTACT ATHEREFOR New Jersey Application December 1,1937, Serial No. 177,454

1 Claim.

This invention relates to an improved electrical connecter and particularly to the improved spring strip metal contact blade used therein. The invention also relates to the method of making the blade.

Heretofore in the manufacture of spring contacts from strip metal, the spring action has been produced by bending one end of the strip of metalbackwardly from the front end of the blade so that the bent back end formed the contact portion of the blade. When the blade was inserted in the receptacle the bent back end was nexed at the bend. Such exing action in the bend often caused the contact to break at this point. Furthermore as the spring action on the contact portion was produced almost entirely by resistance to flexing, at the bend, the spring'action was weak and did not eectively cause the blade to exert sucient pressure on the receptacle at the proper point to form a good contact and to hold the connecter in the receptacle.

In .accordance with the present invention the Contact blade is made from a strip of spring metal which is suitably punched to provide anchoring projections, conductor connecting and locking apertures. The strip is then bent at its middle point, and doubled back on itself so that the ends come together and form the contact end of the blade and the bent end with the anchoring projections thereon forms the anchoring end of the blade. The doubled portions of the strip immediately adjacent the free ends are spaced from one another while such portions are adapted to contact with one another at the free ends and on the other side of such space. Such spaced portions form the spring Contact for the blades. As the spring contact portions are supported at both ends they produce a strong resilient action on the sides of the receptacle, which in conjunction with the resilient shoulder formed by the outwardly curved spring contact portions, act to produce a good contact with the receptacle and also to secure the connecter to the receptacle.

The foregoing features and objects of this invention are hereinafter described in detail in reference to the accompanying drawing, in which: Fig. 1 is a cross-sectional view of an electrical connecter and the improved contact blades embodying this invention and showing the cooperation between the connecter and a receptacle, the inneriends of the connecter contact blades being shownin full.

Fig. 2 is a plan View of a punched out strip of Vmetal from which a contact blade may be made;

and

Fig. 3 is an isometric view of a nished contact blade.

This invention is illustrated in reference to a male electrical connecter 5. The cooperation between the connecter 5 and a receptacle6 of the usual construction is illustrated in Fig. l. The connecter 5 comprises a body 1 which is preferably made of soft rubber as shown herein. The body 'I is provided with a central passage 8 which receives va cord 9 having two conductors IIJ incorporated therein. Contact blades II are electrically connected to the conductors I0 and are secured in recesses in the body l by anchoring projections I2 extending therefrom and into the rubber body. The conductors I0 extend intothe connecting holes I3 in the contact blades II and are secured thereto by solder.

rIhe contact ends I4 of the blades Il are provide With spring contacting portions I5 which are adapted to make contact With the contacts I6 in the receptacle 6 of the usual construction. The spring contacting portions I5 are provided with retaining holes I1 which cooperate With the knobs I9 on receptacle contacts I6.

Referring to Fig. 2, the contact blades II are made from a strip 20 of metal into which are stamped the conductor connecting holes I3, and connecter retaining hole I'l, and the outline of the anchoring projections I2. The projections I2 are at the same time bent outwardly and the ends oi the strip 20 are bowed outwardly in'the direction of the projections I2 to form the spring contacting portions I5. The strip 20 is then bent at its middle point 2| and doubled back on itself so that the ends 22 come together as shown in Figs. 1 and 3 to make the blades I I. If necessary the blades are tempered to provide the desired spring action to the spring contacting portions I5 which are spaced from one another and supported at the point 23 and at the ends 22 when in the receptacle 6, but the ends 22 may be spaced away from each other slightly when out of the receptacle.

When the contact blades Il of the connecter 5 are inserted into the receptacle 6 the shoulders 24 pass over the rounded resilient shoulders 25 on the contacts I6 ofthe receptacle 6 and the retaining holes I1 fit' over the knobs I9 of the contacts I6. The shoulders 24 assisted by the holes l1 acting on the knobs I9 secure the receptacle to the connecter.

Due to the fact that the spring contactingv portions I5 of the blades Il are supported at the two. points 22 and 23 a strong spring action is exerted between the Vside of the recess in the receptacle and the contact I6 by the spring contacting portions I5.

When the blades H are inserted in the receptacle 6 the portions l5 are pressed together from the position shown in Fig. 3 to the position shown in Fig. 1. If the spring in the contact IG is lost and it remains permanently over against the side of the recess in the receptacle, the distance be* tween spring contacting portions l 5 is sufficiently great to make contact even though the contact I6 is out of shape.

While the preferred form of this invention has been illustrated and described in detail herein, it will be understood that changes in such details may be made without departing from the spirit of the invention and the scope of the appended claim.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

The combination of a connector and a recep ltacle, said receptacle having recesses and conof the bowed portions of said connector blades 10 being adapted to spring over the crests of the bowed portions of the receptacle contacts, and when so positioned said bowed portions of said connector blades being compressed between the walls of said recesses and resiliently retained in 15 position by the interlocking spring action of the cooperating bowed portions on the respective receptable contacts and connector blades.

RAYMOND A. WALKER. 

